function s = source(N)
%SOURCE Summary of this function goes here
%   Detailed explanation goes here

s = zeros(1, N);
is_real = round(rand(1,N));
sign = round(rand(1,N));

for j=1:length(s)
    if is_real(j)
        if sign(j)
            s(j)=1;
        else
            s(j)=-1;
        end
    else
        if sign(j)
            s(j)=i;
        else
            s(j)=-i;
        end
    end
end

end

